Association of ALBI score with risk of critically ill patients with COPD: a retrospective study based on MIMIC-IV

The albumin–bilirubin (ALBI) score is a novel marker linked to an adverse prognosis in many diseases. Nevertheless, its predictive value for the risk of mortality in COPD has been rarely explored. Therefore, this study delves into the association of ALBI score with the risk of mortality in patients with COPD. Data from Multiparameter Intelligent Monitoring in Intensive Care IV (MIMIC-IV) 3.0 were reviewed. The associations of ALBI scores with patients' short and long-term all-cause mortality were investigated using Kaplan–Meier curves, COX regression models, and receiver operating characteristic (ROC) curves, and the potential nonlinear relation was explored by restricted cubic spline (RCS) curves. The predictive value of ALBI scores for the risk of mortality was evaluated by ROC curves. In addition, subgroup analyses and propensity score matching were conducted. Among 3325 included patients, Kaplan–Meier curves demonstrated significant survival disparities across ALBI groups at 30, 90, 180, and 365 days (log-rank P < 0.0001). Multivariable COX regression identified ALBI as an independent predictor of 30-day mortality (HR = 1.76, 95% CI 1.35–2.29, *P* < 0.001) and long-term mortality. RCS revealed a nonlinear association (*P*nonlinear < 0.05). ROC analysis confirmed ALBI's predictive capacity for 30 day mortality (AUC = 0.711, 95% CI 0.6743–0.7478). Subgroup analyses showed consistent associations without interaction effects (*P*interaction > 0.05). Propensity score-matched cohorts validated ALBI's positive correlation with mortality across all timepoints. The ALBI score has a significant association with an elevation of mortality risk in critically ill patients with COPD, which can act as a predictor for the COPD prognosis.